Search Publications
Stars That Approach within One Parsec of the Sun: New and More Accurate Encounters Identified in Gaia Data Release 3
Bailer-Jones, C. A. L.
Close encounters of stars to the Sun could affect life on Earth through gravitational perturbations of comets in the Oort cloud or exposure to ionizing radiation. By integrating orbits through the Galactic potential, I identify which of 33 million stars in Gaia DR3 with complete phase space information come close to the Sun. 61 stars formally appr…
NuSTAR Observations of AGNs with Low Observed X-Ray to [O III] Luminosity Ratios: Heavily Obscured AGNs or Turned-off AGNs?
Stern, Daniel; García, Javier A.; Malkan, Matthew A. +2 more
Type 2 active galactic nuclei (AGNs) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of hundreds to thousands of parsecs, but they lack the broad emission lines from close in to the black hole that characterize type 1 AGNs. The lack of broad emission could indica…
Accretion Disk Outflow during the X-Ray Flare of the Super-Eddington Active Nucleus of I Zwicky 1
Ho, Luis C.; Ricci, Claudio; Li, Ruancun +1 more
We present a detailed X-ray spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, for which a sequence of X-ray flares were detected during a long, simultaneous observation acquired with XMM-Newton and NuSTAR. We determine the key parameters of the inner accretion disk and hot corona in the context of the disk reflection model, which s…
The Effect of Current on Magnetic Null Topology during Turbulent Reconnection
Wang, Z.; Cao, J. B.; Liu, Y. Y. +5 more
Using data from the Cluster mission and the First-Order Taylor Expansion method, we investigate the spiral magnetic nulls nested in the diffusion region of turbulent reconnection in the magnetotail. We particularly focus on the relation between the magnetic null topologies and currents, which can be decomposed into a component perpendicular to spi…
Possible Evidence for Shear-driven Kelvin-Helmholtz Instability along the Boundary of Fast and Slow Solar Wind in the Corona
Telloni, Daniele; Zank, Gary P.; Adhikari, Laxman +5 more
This paper reports the first possible evidence for the development of the Kelvin-Helmholtz (KH) instability at the border of coronal holes separating the associated fast wind from the slower wind originating from adjacent streamer regions. Based on a statistical data set of spectroscopic measurements of the UV corona acquired with the UltraViolet …
A Submillimeter Perspective on the GOODS Fields (SUPER GOODS). V. Deep 450 µm Imaging
Barger, A. J.; Cowie, L. L.; Jones, L. H. +1 more
We present deep SCUBA-2 450 µm imaging of the two GOODS fields, achieving a central rms of 1.14 mJy for the GOODS-N and 1.86 mJy for the GOODS-S. For each field, we give a catalog of >4σ detections (79 and 16 sources, respectively). We construct the 450 µm number counts, finding excellent agreement with others from the literature. W…
MiMO: Mixture Model for Open Clusters in Color-Magnitude Diagrams
Li, Lu; Shao, Zhengyi
We propose a mixture model of open clusters (OCs) in color-magnitude diagrams (CMDs) to measure the OC properties, including isochrone parameters (age, distance, metallicity, and dust extinction), stellar mass function (MF), and binary parameters (binary fraction and mass-ratio distribution), with high precision and reliability. The model treats a…
ALMA Observations of Molecular Complexity in the Large Magellanic Cloud: The N 105 Star-forming Region
Tokuda, Kazuki; Onishi, Toshikazu; Kurtz, Stan E. +18 more
The Large Magellanic Cloud (LMC) is the nearest laboratory for detailed studies on the formation and survival of complex organic molecules (COMs), including biologically important ones, in low-metallicity environments-typical of earlier cosmological epochs. We report the results of 1.2 mm continuum and molecular line observations of three fields i…
Detectability of Black Hole Binaries with Gaia: Dependence on Binary Evolution Models
Shikauchi, Minori; Tanikawa, Ataru; Kawanaka, Norita
The astrometric satellite Gaia is expected to observe noninteracting black hole (BH) binaries with luminous companions (LCs; hereafter BH-LC binaries), a different population from BH X-ray binaries previously discovered. The detectability of BH-LC binaries with Gaia might be dependent on binary evolution models. We investigated the Gaia's detectab…
Identification and Spectroscopic Characterization of 128 New Herbig Stars
Panić, Olja; Pérez-Martínez, Ricardo; Oudmaijer, René D. +6 more
We present optical spectroscopy observations of 145 high-mass pre-main-sequence candidates from the catalog of Vioque et al. 2020 From these, we provide evidence for the Herbig nature of 128 sources. This increases the number of known objects of the class by ~50%. We determine the stellar parameters of these sources using the spectra and Gaia EDR3…